Tilt-take-out window assembly

ABSTRACT

The specification and drawings disclose a tilt-take-out window assembly which includes a frame having a pair of spaced apart, generally parallel jamb members which between them define a recess. Guide members in the form of flexible, elongated strips are joined to each of the jamb members to define parallel guide tracks intermediate outwardly extending, raised portions. The flexible strips are joined to the jamb members along at least one of their edges and have a normal configuration to bow into the recess. Window sash members (having lateral edges spaced apart a width very slightly less than the distance between the jamb members but greater than the distance between the strips in their bowed configuration) are positioned between the guide tracks. For example, the window sash members may have lateral edges spaced apart a width about 3/16 inch less than the distance between the jamb members as compared with the usual width of prior art constructions of about 1 3/16 inches less than the distance between the jamb members. The lateral edges of the sash members have guide grooves formed therein to receive the outwardly extending portions of the flexible strips. Additionally, counterbalance spring members are carried in each of the guide grooves and have one end provided with hook members adapted to releasably engage the jamb members. Pivot block means are joined to the other ends of the spring members and are adapted to be connected to the edges of the sash members. Carried in each of the pivot block members is an outwardly biased pin means adapted to engage in a groove in the guide track.

United States Patent Schnormeier Apr. 3, 1973 [54] TlLT-TAKE-OUT WINDOWASSEMBLY [75] Inventor: Theodore H. Schnormeier, Gambier,

Ohio

[73] Assignee: Wenco, 1nc., Mount Vernon, Ohio [22] Filed: Mar. 13, 1972[21] Appl. No.: 234,146

[52] U.S. Cl ..49/l81, 49/446 [51] Int. Cl. ..E05d 15/22 [58] Field ofSearch ..49/176, 181, 446, 453-457,

Primary Examiner-J. Karl Bell Attorney-Jerome R. Cox

[57] ABSTRACT The specification and drawings disclose a tilt-take-outwindow assembly which includes a frame having a pair of spaced apart,generally parallel jamb members which between them define a recess.Guide members in the form of flexible, elongated strips are joined toeach of the jamb members to define parallel guide tracks intermediateoutwardly extending, raised portions. The flexible strips are joined tothe jamb members along at least one of their edges and have a normalconfiguration to bow into the recess. Window sash members (havinglateral edges spaced apart a width very slightly less than the distancebetween the jamb members but greater than the distance between thestrips in their bowed configuration) are positioned between the guidetracks. For example, the window sash members may have lateral edgesspaced apart a width about 3/16 inch less than the distance between thejamb members as compared with the usual width of prior art constructionsof about 1 3/16 inches less than the distance between the jamb members.The lateral edges of the sash members have guide grooves formed thereinto receive the outwardly extending portions of the flexible strips.Additionally, counterbalance spring members are carried in each of theguide grooves and have one end provided with hook members adapted toreleasably engage the jamb members. Pivot block means are joined to theother ends of the spring members and are adapted to be connected to theedges of the sash members. Carried in each of the pivot block members isan outwardly biased pin means adapted to engage in a groove in the guidetrack.

7 Claims, 12 Drawing Figures PATENTEDAPRS I975 I 3.724,l sum 1 BF 6 31 1PATENIEDAPR 3 ma SHEET 2 OF 6 E v V wags:

PATENTEmFRs I975 sum 5 [IF 6 TILT-TAKE-OUT WINDOW ASSEMBLY BACKGROUND OFTHE INVENTION The subject invention is directed toward the window artand more particularly to a window assembly of the type havingtilt-take-out sash units.

A primary object of the invention is the provision of a tilt-take-outsash type window assembly which can be used with standard window frameand sash units.

Tilt-take-out sash type window assemblies are well known and inwidespread use. The typical prior art tilttake-out sash assembly,however, has a relatively complex frame-track assembly and requires sashunits of special size and design (e.g. non-standard). It is well here todefine a standard window frame. Standard window frames are made withdimensions that are accepted in the industry and thus the size can berelied on by architects and builders to be of a size which will fit indimensioned openings. Such standard window frames have an inside widthdimension between the jambs which is a multiple of 2 inches and usuallya multiple of 4 inches. Widths range from 1 foot, 8 inches to 3 feet 8inches (i.e. to 44 inches). Window sash is also normally standardizedexcept for special window sash, as for example, such sash as is designedin the prior art for tilt-take-out window sash. Such standard sash has awidth three-sixteenth inch less than the window frame opening withtolerances of not more than one-sixteenth inch. Because of the generalcomplexity of the prior art tilt-take-out window design, it has not beenpossible to use both standard frame and sash units in such prior artdesigns. Thus, if a company desires to manufacture and sell bothstandard window assemblies and tilt-take-out window assemblies of theprior art designs, two entirely different designs are required in eitherone or both of the frames and sash units.

BRIEF STATEMENT OF THE INVENTION The subject invention overcomes theseproblems and provides a highly simplified assembly in which standardframe and sash units can be used.

According to the subject invention, the assembly includes a frame havinga pair of spaced apart, generally parallel jamb members which define arecess between them. Guide members in the form of flexible, elongatedstrips are joined to each of the jamb members to define parallel guidetracks intermediate outwardly extending raised portions. The stripspreferably are joined to the jamb members along at least one of theiredges and have a normal configuration to bow into the recess. Windowsash members (having lateral edges spaced apart a width slightly lessthan the distance between the jamb members but greater than the distancebetween the strips in their bowed configuration) are positioned betweenthe guide tracks. The lateral edges of the sash members have guidegrooves formed to receive the outwardly extending portions of thestrips. Additionally, counterbalance spring members are carried in eachof the guide grooves and have one end provided with hook members adaptedto releasably engage the jamb members. Pivot block means are joined tothe other ends of the spring members and are adapted to be connected tothe edge of the sash members. Carried in each of the pivot block membersis an outwardly biased pin means (such outwardly biased pin means beingspring loaded pins) adapted to engage the guide track.

According to a more limited aspect of the invention, the flexible stripsare formed from a resilient plastic, such as polyvinylchloride, and arerelatively thin and flexible. They are preferably joined to the frame byan integral flange having a flexible hook formed thereon. The hook has anormal dimension which is slightly greater than the dimension of a slotformed in the jamb member. Thus, the strips can be attached to the jambmerely by forcing the hook member into the slot.' This attaches the sashstrips and also provides an air-tight seal between the jamb and thestrip.

As can be appreciated, the resilient strips resiliently and sealinglygrip the edges of the sash units. However, the sash units slide freelyon the strips. Moreover, to tilt either of the sash units inwardly asfor washing the outside, it is necessary only to remove each of thespring hooks from the cooperating inclined hole in the associated jamband then turn the hooks and position them on the tops of the associatedsash units and thereafter pull the top of the sash unit inwardly. Theouter edges of the sash units cam the strips outwardly and the sashunits pivot about the pins in the pivot blocks. To remove either sash,it is first pivoted approximately to a horizontal position and thenrotated about the perpendicular axis so as to raise (or lower) one ofthe pivot pins relative to the other and release the pivot pins from theguide tracks.

Because of the nature of the sash strip and the counterbalance springmechanisms, the assembly can be used on slightly modified standard, nontilt-out window frames and sash units. Thus, the same basic frame-sashassembly can be used either for a conventional non tiltout window or atilt-out type sash unit. Little or no change need be made to the frameexcept for the formation of slanted holes in the jambs for receipt ofthe hooks supporting the upper ends of the counterbalance spring membersand little or no change need be made to the sash units except for theguide and spring receiving grooves formed in the edges of each sashunit. Substantial cost savings are achieved. The balance system isaccomplished with approximately one third of the cost of priortilt-take-out constructions. The simplicity of the jamb liner formingthe guide tracks also achieves substantial cost savings. The improvedconstruction does not require relatively expensive clutch holdingbalance mechanism.

The above and other objects and advantages will become apparent from thefollowing description when read in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a pictorial view of a typical window assembly incorporatingthe invention;

' FIG. 2 is a substantially enlarged cross-sectional view taken on line2-2 of FIG. 1;

FIG. 3 is an enlarged cross-sectional view taken on line 3-3 of FIG. 1and showing in detail a counterbalance spring assembly of the invention;

FIG. 4 is a cross-sectional view taken on line 4-4 of FIG. 3;

FIG. 5 is an enlarged view of the circled area of FIG.

FIG. 6 is a view of the circled area of FIG. 5 showing the stripattaching hook portion separated from the associated frame slot;

FIG. 7 is an enlarged side view of one of the pivot block members of thecounterbalance sash assembly;

FIG. 8 is a view taken on line 8-8 of FIG. 7;

FIG. 9 is an enlarged cross-sectional view taken on line 9-9 of FIG. 7;

FIG. 10 is a view in perspective similar to FIG. 1 but showing somemodifications and showing the lower sash tilted inwardly;

FIG. 11 is a view in perspective similar to FIGS. 1 and 10, but showingthe lower sash of FIG. 10 rotated from the horizontal position torelease the pivot pins from the guide tracks; and

FIG. 12 is a view in perspective similar to FIGS. 1, 10 and 1 1, showingthe lower sash of FIG. 10 removed and the upper sash thereof loweredpreparatory to either tilting it or removing it.

Referring more particularly to the drawings wherein the showings are forthe purpose of illustrating a preferred embodiment of the invention onlyand not for the purpose of limiting the same, FIG. 1 shows a windowassembly 10 which incorporates features of the invention and comprises arelatively conventional, generally rectangular frame assembly 12 havingupper and lower window sash units 14 and 16 positioned therein. Thesubject device is arranged so that the sash units 14 and 16 can slidevertically in the conventional manner and also can be tilted out of theframe or removed therefrom.

In the embodiment under consideration, the frame 12 is formed from wood;however, it should be appreciated that any desired type of materialcould be used. As best illustrated in FIG. 1, frame assembly 12 includesa pair of vertically extending side frame members or jambs 18 and 20joined at their upper ends by a horizontally extending frame member 22to define a recess which receives the sash units 14 and 16. A sill framemember 24 extends horizontally between the lower end portions of theside frames or jamb members 18 and 20 and is received in suitable dadoesformed in the inner faces of the side frames 18 and 20. The framemembers can be joined in any desired manner; however, in the subjectembodiment, they are simply nailed.

The upper and lower window sash units 14 and 16 are mounted within therecess defined by the frame 12 and are arranged for conventionalvertical sliding movement. The upper sash unit 14 is illustrated asincluding a pair of vertical side members 26 and 28 connected byhorizontally extending upper and lower frame members 30 (notillustrated) and 32, respectively. Glass 34 is suitably sealed withinthe frame defined by members 26, 28, 30 and 32. The lower sash unit 16is similarly formed and includes the side members 35 and 36 and theupper and lower members 38 and 40. A sheet of glass 42 is mounted in thelower sash frame. FIG. 1 illustrates the sash members in their closedposition and a conventional cam-type sash lock 49-49a is arranged tohold them in this closed position.

Of particular importance to the subject invention is the manner in whichthe window sash units 14 and 16 are mounted within the frame assembly12. The assembly is designed such that the frame assembly 12 is lesscomplex and the construction of the window guides is much simpler thanprior art units. Additionally, the construction allows the sash units tobe readily tilted inwardly and/or, if desired, removed for cleaning,maintenance and the like. As best shown in FIGS. 1, 2 and 5, the guidetracks for the vertical sliding movement of the sash units 14, 16 aredefined by resilient, vertically extending strip members 50. One of thestrips 50 extends substantially the entire length of the inner surfaceof each of the side frame or jamb members 18 and 20. In the embodimentunder consideration, the strips 50 are formed from a suitable plastic,such as polyvinylchloride, and are preferably configured so that theycan be made by a simple extrusion process. That is, they are ofconstant, uniform cross-section throughout their length. As best shownin FIGS. 2 and 5, each strip 50 defines a pair of vertically extendingguide tracks 52 and 54 (see FIG. 2) which extend the entire length ofeach strip 50. Adjacent each of the guide tracks or grooves 52 and 54are raised sections 56 and 57, and 56' and 57', respectively.

Although the raised sections 56 and 57 are illustrated as having sidewalls inclined at 45, this angle could vary in the range of fromapproximately 30 to approximately 60. It should be noted that the edgesof each of the sash units 14 and 16 have grooves 58 formed along theiredges. The grooves 58 preferably have a semicylindrical bottom wall 59and outer edges shaped to receive and embrace the raised portions 56 and57 of the side strips 50. Additionally, referring to FIG. 5, it will benoted that the side strips 50 preferably have an unstressed or normalconfiguration which bows outwardly between the lateral edges of thestrips. FIG. 5 illustrates the .unstressed normal bowed position of theside strips 50 with the dotted line showing identified with the number50a. As can be appreciated, when the sash units are placed in positionwith the raised portions 56 or 57 received in their side grooves, thestrips 50 are compressed to the solid line position. This maintains thestrips in tight sealing engagement with the edges of the sash whilepermitting the sash to slide freely along the side strips.

The strips 50 could be connected to the frames in many ways; however, inthe subject embodiment, each of the side strips 50 preferably includes alaterally extending flange portion 60 (see FIGS. 5 and 6) whichterminates in a hook member 62. The width of hook member 62 isidentified with a W as shown in FIG. 6. The flange 60 and the hookmember 62 are arranged to be received in a slot or groove 64 formedalong the corresponding side frame members. The slot 64 has a width Twhich is less than W. Accordingly, the side strip can be placed with thehook over the slot 64 and then driven into the groove. The shape of thehook is such that it acts to grip the sides of the slot 64 to preventwithdrawal. This provides a simple method for connecting the side strips50 and, additionally, it assures an air-tight seal between the sidestrips 50 and the frame. The edge of the side strips 50 opposite theflange 60 can remain loose, or, for example, they can be received in aslot formed in a blind stop 65 connected to frame member 20 along thelength of the frame.

As can be seen, the described side strip arrangement allows readyassembly of the window unit and permits free vertical sliding movementof the sash units. Additionally, the configuration of the sash strip issuch as to maintain a tight seal about the sash units. Moreover, itshould be noted that the frame components can be relatively simple withslight modifications from conven-. tional frame units. Thus, the frameis a standard or conventional frame except for the slots or grooves 64and except for holes 84 later to be described.

Referring to FIG. 2, it will be seen that the sash units 14 and 16embrace and are guided by raised sections 56 and 57 and 56a and 57'.When the sashes are in the closed position as illustrated in FIG. 1,their respective lower and upper edges are adjacent each other. Aresilient seal strip (shown in section at 71) is preferably attached toone or the other of the sash members to maintain a tight seal. At theends of the seal strip, resilient foam blocks or the like 66 areconnected to one or the other of the sash units so that an air-tightseal is maintained at the ends of the seal strip between the sash unitsand the side strips 50. For example, in the subject embodiment, theresilient blocks 66 are connected to the upper sash 14 and extendinwardly sufficiently for engagement with the surface of the lower sash16.

The structure thus far described could be used without counterbalanceassemblies if desired. If so used, it is possible to remove the sashinwardly out of the frame merely by releasing the cam lock 49 andraising the lower sash unit a short distance. Thereafter, the sash unitcan be pulled inwardly, and, as shown in dotted line 50b in FIG. 5, theside strips 50 on each side will be cammed outwardly by the cooperatingsurfaces of the sash strip and the grooves 58 in the edge of the sash.Dotted line showing 50b illustrates the position of the side strip asthe window is pulled from the frame.

A relatively important aspect of the subject invention, however,concerns the arrangement of counterbalance spring assemblies associatedwith each of the sashes 14 and 16. FIGS. 3 and 4 illustrate thepreferred form of the counterbalance spring assemblies. Note that a pairof counterbalance spring assemblies 74 are associated with the lowersash 16 (one of the pair being illustrated in FIG. 3). A similar pair ofcounterbalance spring assemblies 72 (one of the pair being shown in FIG.4) are associated with the upper sash 14. Because the assemblies 72, 74are substantially identical (same length) only one will be described indetail, and the description thereof is to be taken as equally applicableto the others except where noted.

In particular, each of the counterbalance spring assemblies includes afirst hook block member 75 adapted to be releasably connected with theframe. Block members 75 are preferably formed from plastic and have agenerally cylindrical main body 76 provided with laterally inwardlyextending recesses 78. Recesses 78 provides a convenient portion forgripping, for reasons which will subsequently be explained. Extendinglaterally from the main body 76 is a hook 80 having a generallyrectangular cross-section and provided with a plurality of shortserrations or teeth 82. Preferably, and for reasons which will hereafterbecome apparent, the hook portion 80 is downwardly inclined slightly. Inthe subject embodiment, the angle of inclination is preferablyapproximately forming an included angle of 80 between the hook memberand the axis of the main body. The hook is arranged to removably engagewith the side frame. As shown in FIG. 3, an inclined hole 84 is formedinto the associated side frame at an angle corresponding to the angle ofthe hook portion 80. The hole 84 is preferably slightly greater indiameter than the total width of the hook member over the tooth portion82. This allows easy insertion and removal of the hook.

Extending downwardly from the cylindrical body portion 76 is a hook 86adapted to receive the end of a coil spring 88. The coil spring 88 has adiameter to fit easily within the sash side groove 58 and is sized sothat it will nearly counterbalance the weight of the lower sash member16.

The lower end of spring 88 is connected to the lower edge portion of thesash unit 16 by a pivot block assembly 92. The pivot block assemblies 92are arranged to be received within the vertically extending grooves 58formed in the lateral side edges of the sash members. As best shown inFIGS. 7 through 9, each of the pivot block members 92 includes a mainbody 94 having a semi-cylindrical wall which is sized so as to closelyfit within the semi-cylindrical groove 58. An opening 96 extends throughthe body from a triangular recess 97. This allows a screw or the like tobe passed through the opening into engagement with the sash. Forexample, a screw 98 is shown connecting the sash block 92 to the lowersash assembly 16. A hook portion 100 extends upwardly from the upper endof the body 94 for engagement with the lower end of the spring 88. Thespring 88 is sized so that it has an extended length sufficient toextend from the upper portion of the frame to the lower portion of theframe and when in this extended position the force exerted by it nearlycounterbalances the weight of the lower sash 16.

In the embodiment under consideration, the exposed portion of the springis enclosed by a plastic tube 102 which extends from the hook blockassembly 74 to a position slightly below the upper edge of sash unit 16.This presents a clear appearance, and also prevents the spring fromcatching the upper edge of the sash. Additionally, it will be noted thatthe lower end of the hook block 75 has a reduced diameter portion whichfits closely within the plastic tube 102. The tube is connected to thehook block 75 in any convenient manner such as through the use of across pin 104 which extends through an opening formed in the hook block.

One feature of particular importance to the pivot block assembly 92 isthe provision of a spring biased guide and tilt pin member 106 which isadapted to fit within the corresponding side strip or track 54. As bestshown in FIGS. 7 through 9, the tilt pin 106 has a generally rectangularbody portion 108 which is received within a rectangular opening 110formed through the tilt block body 94. The outer end of the pin 106 iscircular and has a diameter slightly greater than the opening across theend of opening 110. This allows the pivot pin to be pushed from the leftthrough opening 110 and snap its head portion 120 through the smallflanges 122 formed in the tilt block body. The opposite end of the tiltblock body is provided with small outwardly extending tabs or flanges124 which prevent the block from being moved to the right out of theopening 110 (as viewed in FIG. 9). The left hand end of tilt pin 106 hasa reduced diameter portion 113 having at its left hand end a head 114which is arranged to enter the end convolution of a compression spring116 to removably attach the spring to the pivot pin. When the tilt blockis assembled into the sash (as shown in FIGS. 3 and 4), the tilt pin isbiased into tight engagement with the corresponding guide groove 52 or54 of the strip 50. This provides a positive engagement between the sashand the guide grooves while permitting removal of the sash or tilting ofthe sash out of the frame assembly.

To explain the operation and the simplicity of the tilting or removaloperation, reference is made to FIGS. 1, 2, 10, l1 and 12. If it isdesired to, for example, remove the lower sash 16 from the frame, allthat is necessary is that the hook members 80 on each side be liftedupward slightly, disengaging their teeth 82 from the side of the hole84. They can then be pulled out of the hole and rotated and moveddownward so that they engage the upper surface of the lower sash unit 16(as shown in FIGS. 10 and 11). With the hook assemblies on each side ofthe sash unit removed and moved to a lower position, the top edge of thesash unit 16 can be gripped and pulled outwardly, camming the sidestrips 50 laterally and permitting the upper portions of the sash to betilted out of the frame. The heads 120 of the pivot pins 106 in each ofthe lower tilt block assemblies will remain firmly engaged in the guidegrooves, however. The sash unit 16 is, of course, tilted into the roomas shown in FIG. 10 and the outside surface of the glass can be cleanedor the like.

If it is desired to completely remove the sash unit 16 from the window,it can be rotated slightly (as shown in FIG. 11) to remove one of thepivot pins 106 from engagement with its guide groove after which theother pivot pin can similarly be removed and the entire sash unitremoved (as shown in FIG. 12).

A similar sequence of operations allows the upper sash unit 14 to beremoved; that is, the upper sash can be moved either a short or longdistance, exposing the hook members 80 which can be removed from theirengagement with the frame and moved into engagement with the top surfaceof the corresponding sash. After this, the sash can be tilted inwardly,camming over its own raised portions and the raised portions of thelower sash guide groove to a position in which it is tilted into theroom. Thereafter, it can be rotated slightly, disengaging its pivot pinsfor removal from the window frame.

For ease of description, the principles of the invention have been setforth in connection with a single embodiment. It is not intended thatthe illustrated embodiment nor the terminology employed in describing itbe limited inasmuch as variations in it may be made by one of ordinaryskill in the art without departing from the spirit of the invention.Rather, it is desired to be restricted only by the scope of the appendedclaims.

What is claimed is:

l. A window assembly comprising:

a substantially standard window frame including a pair of spaced apart,generally parallel jamb members defining a recess;

strip members joined to each of said jamb members, each of said stripmembers including an elongated, relatively thin, strip of materialjoined to its respective jamb member along at least one edge portion andhaving a normal configuration to bow away from said jamb into saidrecess, and having a first elongated strip guide groove formed in eachsaid strip at a location spaced inwardly from and generally parallel tosaid edge portion, and portions of each said str i on each side of andadacent said strip gui e groove being inclined toward said frame recess;

a substantially standard window sash member having lateral edges spaceda width less than the distance between said jamb members but greaterthan the distance between said strips in their normal, bowedconfiguration; said sash member having grooves formed inwardly alongopposite lateral edges of said sash, said sash grooves each being formedto receive the inclined portions of said strips when said sash member isplaced between said strips;

counterbalance spring members carried in each of said sash grooves andeach having a first end connected to said sash by pivot block means atone end of its respective sash groove and having a second end connectedto said frame, each said pivot block means including a pin member biasedoutwardly into said strip guide groove.

2. The window assembly as defined in claim 1,

wherein the second end of each said spring member is connected to saidframe by a connecting member size to fit within said sash groove andhaving an integral laterally extending portion removably received in ahole formed in the respective jamb member.

3. The window assembly as defined in claim 2,

wherein said hole and said laterally extending portion are inclined in adirection toward said first end of said spring members.

4. The window assembly as defined in claim 1,

wherein said pivot block means comprise relatively rigid block memberspositioned in each sash groove and having an outwardly facing surfaceadapted to slidingly engage the associated strip member, said pinmembers extending out of said outwardly facing surfaces and biased intothe associated strip guide groove by a spring carried in the blockmember.

5. The window assembly as defined in claim 1,

wherein said side strip members are formed of plastic and are joined totheir respective jamb members by tabs forced into slots formed in saidjamb members.

6. The window assembly as defined in claim 1,

wherein said second end of said spring can be readily disconnected fromsaid frame, and wherein said strips are sufficiently resilient to allowsaid sash members to be moved out of said frame by deflecting saidstrips and tilting of the sash member about said pin members.

7. The window assembly as defined in claim 6, in-

cluding a second sash member;

said strips each including a second strip guide groove parallel to saidfirst strip guide groove;

said second sash being slidingly received between said strips; and

including pin members extending into said second strip guide groove.

* t l i Patent No. 3,72L 131 Dated April 3, 1973 Inventor) Theodore H.Schnormeier It; is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 5, lines 51-52 should read! Recesses 78 provide a convenientportion for gripping rather than Recesses 78 provides..

Column 6, line 35, 'This presents a clear appearance" should read Thispresents a clean appearance This certificate supersedes theCertificateof Correction issued August ll 1973.

Signed and sealed this 26th day of March 197A.

(SEAL) Attest:

EDWARD M.FLETCIER,JR. C. MARSHALL DANN Attesting Officer Commissioner ofPatents FORM PO-10 0 (10-69) uscoMM-Dc 60376-P69 U.S. GOVERNMENTPRINTING OFFICE I969 0-366-334,

1. A window assembly comprising: a substantially standard window frameincluding a pair of spaced apart, generally parallel jamb membersdefining a recess; strip members joined to each of said jamb members,each of said strip members including an elongated, relatively thin,strip of material joined to its respective jamb member along at leastone edge portion and having a normal configuration to bow away from saidjamb into said recess, and having a first elongated strip guide grooveformed in each said strip at a location spaced inwardly from andgenerally parallel to said edge portion, and portions of each said stripon each side of and adjacent said strip guide groove being inclinedtoward said frame recess; a substantially standard window sash memberhaving lateral edges spaced a width less than the distance between saidjamb members but greater than the distance between said strips in theirnormal, bowed configuration; said sash member having grooves formedinwardly along opposite lateral edges of said sash, said sash grooveseach being formed to receive the inclined portions of said strips whensaid sash member is placed between said strips; counterbalance springmembers carried in each of said sash grooves and each having a first endconnected to said sash by pivot block means at one end of its respectivesash groove and having a second end connected to said frame, each saidpivot block means including a pin member biased outwardly into saidstrip guide groove.
 2. The window assembly as defined in claim 1,wherein the second end of each said spring member is connected to saidframe by a connecting member size to fit within said sash groove andhaving an integral laterally extending portion removably received in ahole formed in the respective jamb member.
 3. The window assembly asdefined in claim 2, wherein said hole and said laterally extendingportion are inclined in a direction toward said first end of said springmembers.
 4. The window assembly as defined in claim 1, wherein saidpivot block means comprise relatively rigid block members positioned ineach sash groove and having an outwardly facing surface adapted toslidingly engage the associated strip member, said pin members extendingout of said outwardly facing surfaces and biased into the associatedstrip guide groove by a spring carried in the block member.
 5. Thewindow assembly as defined in claim 1, wherein said side strip membersare formed of plastic and are joined to their respective jamb members bytabs forced into slots formed in said jamb members.
 6. The windowassembly as defined in claim 1, wherein said second end of said springcan be readily disconnected from said frame, and wherein said strips aresufficiently resilient to allow said sash members to be moved out ofsaid frame by deflecting said strips and tilting of the sash memberabout said pin members.
 7. The window assembly as defined in claim 6,including a second sash member; said strips each including a secondstrip guide groove parallel to said first strip guide groove; saidsecond sash being slidingly received between said strips; and includingpin members extending into said second strip guide groove.